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This guide covers an example OpenID Connect plugin configuration to authenticate browser clients using an Okta identity provider.
Because OpenID Connect deals with user credentials, all transactions should take place over HTTPS. Although user passwords for third party identity providers are only submitted to those providers and not Kong, authentication tokens grant access to a subset of user account data and protected APIs, and should be secured. As such, you should make Kong’s proxy available via a fully-qualified domain name and add a certificate for it.
If you have not yet added a Route and a Service, go ahead and do so. Again, note that you should be able to secure this route with HTTPS, so use a hostname you have a certificate for. Add a location handled by your route as an authorized redirect URI in Okta (under the Authentication section of your app registration).
Okta IDP Configuration
Sample Okta Configuration Steps
Register an Application. Select the Applications page, click Add Application.
Select Web as the platform.
Fill out the Application’s Settings
Login re-direct URIs is a URI that corresponds to a Route you have configured in Kong that will use Okta to authenticate. Group Assignment defines who is allowed to use this application. Grant Type Allowed indicates the Grant types to allow for your application.
After submitting the Application configuration, the client credentials will display on the General page.
Define and configure an Authorization server. Select the API page and add an Authorization Server if you don’t have an existing one to use.
Click Save and view your Authorization Server Settings.
Add a plugin with the configuration below to your route using an HTTP client or Kong Manager.
$ curl -i -X POST https://admin.kong.example/routes/ROUTE_ID/plugins --data name="openid-connect" \
--data config.issuer="https://YOUR_OKTA_DOMAIN/oauth2/YOUR_AUTH_SERVER/.well-known/openid-configuration" \
--data config.client_id="YOUR_CLIENT_ID" \
--data config.client_secret="YOUR_CLIENT_SECRET" \
--data config.redirect_uri="https://kong.com/api" \
--data config.scopes="openid" \
--data config.scopes="email" \
Several pieces of configuration above must use values specific to your environment:
issuer URL can be found from your Authorization Server settings.
redirect_uri should be the URI you specified earlier when configuring your app. You can view and edit this from the General page for your application.
YOUR_CLIENT_SECRET with the client ID and secret shown in your Okta application’s General page.
Visiting a URL matched by that route in a browser will now redirect to Okta’s authentication site and return you to the redirect URI after authenticating.
Additional plugin parameter to consider:
auth_methods parameter defines a lists of all the authentication methods that you want the plugin to accept. By default value is a list of all the supported methods. It is advisable to define this parameter with only the methods you wish to allow.
The configuration above allows users to authenticate and access the Route even though no consumer was created for them: any user with a valid account in the directory will have access to the Route. The OIDC plugin allows this as the simplest authentication option, but you may wish to restrict access further. There are several options for this:
If you need to interact with other Kong plugins using consumer information, you can add configuration that maps account data received from the identity provider to a Kong consumer. For this example, the user’s Okta’s AD account GUID is mapped to a consumer by setting it as the
custom_id on their consumer, e.g.
$ curl -i -X POST http://admin.kong.example/consumers/ \
--data username="Yoda" \
$ curl -i -X PATCH http://admin.kong.example/plugins/OIDC_PLUGIN_ID \
--data config.consumer_by="custom_id" \
Now, if a user logs into an Okta account with the GUID
e5634b31-d67f-4661-a6fb-b6cb77849bcf, Kong will apply configuration associated with the consumer
Yoda to their requests.
This also requires that clients login using an account mapped to some consumer, which may not be desirable (e.g. you apply OpenID Connect to a service, but only use plugins requiring a consumer on some routes). To deal with this, you can set the
anonymous parameter in your OIDC plugin configuration to the ID of a generic consumer, which will then be used for all authenticated users that cannot be mapped to some other consumer. You can alternately set
true to allow similar logins without mapping an anonymous consumer.
For plugins that typically require consumers, the OIDC plugin can provide a consumer ID based on the value of a claim without mapping to an actual consumer. Setting
credential_claim to a claim in your plugin configuration will extract the value of that claim and use it where Kong would normally use a consumer ID. Note that this may not work with all consumer-related functionality.
authenticated_groups_claim will extract that claim’s value and use it as a group for the ACL plugin.